Condenser testing system



May 13, 1952 F.v J. FOUST ET'AL CONDENSER TESTING SYSTEM 6 Sheets-Sheet l 7 Filed July 29, 1946 [NI/5115K BY y 13, 1952 F. .1. FOUST ET AL 2,596,396

CONDENSER TESTING SYSTEM Filed July 29 1946 6 Sheets-Sheet 2 y 3, 1952 F. J. FOUST ET AL CONDENSER TESTING SYSTEM 6 Sheets-Sheet 3 Filed July 29, 1946 IN VEN TORS May 13, 1952 F. J. FOUST ET AL CONDENSER TESTING SYSTEM 6 Sheets-Sheet 4 Filed July 29, 1946 h mu NVENTOR. zz/w/ma/ 2% [QM M y 13, 1952 F. J. FOUST ET AL 2,596,396

CONDENSER TESTING SYSTEM Filed July 29, 1946 6 Sheets-Sheet 5 6 f 11- a q CAM 77/7/N6 CONTROL F. J. FOUST ET AL 2,596,396

CONDENSER TESTING SYSTEM 6 Sheets-Sheet 6 m 1 M WW w R m 1 m 1 i 2 M I L 0 W W 6 1.. H C I 4 1:1 0 7 Y J F m m. N z j 3 HM n In E 7 a 7 M 2 H a R 7 A R W i 7 3 3 W l 4 I 1 7 V u/ M V i \W J \J A 2 J v 5 mm s m 4 WW. l V/ 2 a A 7 a 7 4 W15 .4 A W3 A fi 7 7 fl t 3 W \Y R Z 7 Y A 7 1 F 4 n. v M Mwu A 7 Z W/ A v: FILE Z Y 1T \n 2m 1 R m. w J 7 I E W Y 7 M W R w 5 6 M w M 5 M a m a l E fl I B 7 m W I W 8 R Z \Y 7 /u 7 7 7 L a v M .27, m 4 M m a E a W R M, w W W R a 0 7 a E 4 f 7 a In I: T 4 Y 1 w Va 7 A R 7 7 H R m N d W N R W k Y W. Y 7 7 C 7 H R i M W A n s. la I. mm m .n w \V V J m m X m E m TEST TEST CONDENSER CAPAC TY CAPAC TY SHORT CAPAC TY G000 UNDER OVER May 13, 1952 Filed July 29, 1946 Patented May 13, 1952 CONDENSER TESTING SYSTEM Floyd J. Foust, Willard C. Shaw, Hilton J. McKee,

Warren M. Rider and James S. Burge, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation *of Delaware Application July 29, 1946, Serial No. 686,964

7 Claims.

. This invention relates to the manufacture of electrical condensers and more particularly to condenser having a foil winding enclosed in a metal can to which one foil of the condenser is' electrically connected, the other foil being electrically connected to a wire extending from the can and insulated therefrom.

The invention relates more particularly to testing apparatus used with a machine which facilitates the attachment of a terminal clip to the condenser lead wire and the welding of the clip to the Wire and the inspection of the condenser. This machine provides an intermittently operating conveyor having work holders for receiving the condensers, a punch press for forming a terminal clip and attaching it to a condenser wire when the condenser has been conveyed to theclip attaching station and an electric welding apparatus which applies electrodes to the clip and wire and causes a welding current to pass when the condenser has been conveyed to the clip Welding station. As the condensers are conveyed from a loading station toward the clip attaching station they are automatically tested for capacity and short-circuit; and those condensers which do not pass the tests are automatically ejected from the conveyor. The machine provides means for operating the conveyor, press, welding and testing apparatus in timed relation. The machine provides counters counting the good condensers,

those which fail in short-circuit test and those Fig. 2 is a view in the direction of arrow 2 of Fig. 1. Fig. 3 is a view in the direction of arrow 3 of Fig- 1.

, Figs. 4-8 are winding diagrams of the condenser testing apparatus.

Referring to Fig. l, which shows, in section, a conveyor chain I!) which moves work holders W along a conveyor track ll, each work holder receives a condenser CT to be tested from which extends a lead wire I.

Fig. 1 shows a cam 420 driven by shaft l6! and engageable with a roller 42| carried by a lever 422 pivoted at 423 on a bracket 424 supported by the plate 365. Lever 422 includes arms 425 and 425 (Fig. 2) connected respectively by links 421 and 428 with levers 429 and 430 respectively pivoted at 433 upon abracket 434 attached to 'ch'ahnel iii of the machine frame and provided respectively with insulatingly supported pincer jaw plates 43l and 432 for engaging the hatred end of the condenser lead wire I (Fig. 1). Plates 43l, 432 are connected with a wire leading to the testing apparatus which will be described later. The lever 422 is urged counterclockwise by a spring 44%) surrounding a rod 44! attached to the lever 422 and supported by a bracket 4'42 attached to the channel it. Spring 440 is confined between brackets 442 and a shoulder or nut 443 of the rod 44!. The cam 42!) opens the 'jaws 43L 432 by a clockwise movement of the lever 422 against the action of spring 440. To hold the jaws open when the testing apparatus is not being used, there is provided a lever 445 pivoted at 446 on bracket 4:22 (Fig. 3). Lever 445 has a notch 44'! for receiving the rod 441, said notch being narrower than the head 448 attached to: the rod. Therefore, if the jaws are opened, as a result or clockwise movement of lever 422 and upward movement of rod 441, the head 448 will be above the upper surface of the lever 4'45 and if this lever is then moved counterclockwise (Fig. 3) the notch e41 will receive the rod 44! and the head 448 will be above the lever 445 so that the spring cannot return the lever 422 to the position shown in Fig. 1 although the cam 42!] would be in position to permit the spring to do so. Therefore, the jaws '43! and 432 will be held apart. The lever 445 is controlled by moving a knob 459 provided by an arm 45! extending from a tubular shaft 452 pivoted at 153 upon a channel 10 and having arms 454 and 455. Arm 454 is connected by a link 456 to an arm 455. Arm 455 is connected by the rod 499 with the lever which carries a pin 402 which is associated with a mechanism not shown for disabling an ejector of defective condenser. When the knob 450 is moved clockwise looking in the direction of arrow 450a (Fig. 3 at the time rod 44] is up (Fig. 1), the jaws 43!, 432 are not allowed to grip the condenser lead and the ejector is disabled.

Testing apparatus Each condenser is tested for short circuit by a high voltage D. C. (flash) test. If an appreciable direct current passes through the condenser, an ejector M is caused to operate to remove the bad 3 condenser from the conveyor and it will pass down a chute. If no appreciable direct current passes through the condenser, it remains a charged condenser until discharged during the R--C (resistance-capacity) test. If its discharge is unsatisfactory it will be ejected. If it passes the discharge test as well as the short circuit test, a circuit of the low and high capacity test is established. It will pass the low and high capacity test provided it will pass current between certain low and high values when connected in a resonant circuit which may comprise, for example, a source at 110 volts A. C., a voltage divider, an inductance, a lamp and the condenser. For example, the lowest allowable capacity can be when the condenser passes .18 milliampere, and the highest allowable capacity when the condenser passes .23 milliampere. The ability of the condenser to pass current when discharging in the resonant circuit is determined by the candie- 3 power of the lamp whose rays are directed upon two photo-electric cells respectively controlling the grid biases of two thyratron tubes which effect a control over apparatus which will cause the ejector to remain non-operative to remove the condenser (which has passed the-flash test) provided it passes current in the resonant circuit between the low and high limits. If the condenser passes too little or too much current, the

tubes cause the ejector to operate to remove the .condenser from the conveyor. The machine sorts condensers failing in the capacity test from those which fail in the short test.

Lines l and 2 (Figs. 4 to 8) receive 110 volts A. C. and supply energizing current to various :3

solenoids and A. C. input to the power pack in Fig. 7. Line Ill (Figs. 4 to 8) receives 230 volts D. C. Lines 2| and 22 (Fig. 4 and circuit VIII. Fig. 8) are connected with a source of regulated voltage at 110 volts A. C., and are connected as shown in Fig. 4 with a voltage divider 52G connected with inductance l2! connected with line 20 connected in Fig. 4 with capacity responsive lamp H3 connected with line It. In Fig. 5 line l5 connects with contact cifi of relay C. When the coil I230 of relay C is energized, its movable contact 122 separates from contact 122a and engages contact E5. Contact I22 is connected with contact I24 of relay B connected with the pincer jaws 43! and 432 (Fig. 2) which grip the bare head of the condensers CT to be tested. Thus condenser CT (capacity) is connected in a resonant circuit which includes inductances l2! and a SO-cycle, alternating current source. The amount of current which the condenser CT will pass when connected into the resonant circuit is an indication of its capacity. The candle-power of lamp 1 l 3 in the circuit depends on the amount of current passed by the condenser. The tube lill is so adjusted that it will pass current through its plate 199 when the current passed by CT is at the low limit or higher. The tube W2 is so adjusted that it will pass current only when the current passed by CT exceeds the high limit. For example, the low limit may be .23 milliampere indicating the lowest permissible capacity of the condenser CT; and the high limit may be .28 milliampere indicating the highest permissible capacity of the condenser CT.

If the limits of current passed are to be .23 and .28 milliampere, calibrating condensers, respectively, for passing .23 ma. and .28 ma. are connected with line i by switches not shown. While the condenser known to pass .23 ma. in the resonant circuit is connected into line I5,

grid bias adjuster I03 is adjusted until tube I0! just begins to pass current, then the adjustment is backed off until the tube 'lfil just fails to pass current. While the condenser known to pass .28 ma. in the resonant circuit is connected into line it, grid bias adjuster IE4 is adjusted until tube W2 just begins to pass current. If the capacity of condenser CT is below the minimum, tube nu does not pass current and a contro1 circuit is caused to operate to efiect ejection of the condenser by an ejector not shown. If the capacity of condenser CT is above the minimum, tube 18! will pass current; but, if the capacity is below the maximum, tube 782 will not pass current and the control circuit is so conditioned that the ejector will be disabled so that the good condenser will not be ejected when the time for ejection arrives. However, if the capacity is above the maximum, tube E62 will pass current andthe control circuit will be conditioned for permitting the ejector toremove the condenser and a trap valve will be operated to cause the condenser to be diverted from a chute through which short test failures descend to a chute in which capacity test failures descend.

Before the capacity test the condenser CT is subjected to a high voltage (500 or 750 volts D. C.) flash test for short circuit. For this purpose a D. C. power supply (Fig. '7) receives v. A. C. from lines I and 2 and delivers 560' v. D. C. to line i or 750 v. D. C. to line 8. Switch SWI9 (Fig. 4) connected with line 6 can be connected either with line '1' or line 8 depending on which flash test voltage is desirable. Fig. 5 (left) shows that line 3 is connected with magnet coil 133 of a flash test relay I35 connected with movable contact T25 of relay 13 whose coil 12% is energized when switch SW4 is closed by action of cam 410 in order to connect coil [25 with line H) (230 volts D. C.) connected with line ll) of the D. C. power pack (Fig. '7). When relay B is energized contact T25 engages contact 12'! connected with contact 528 and contact 123 is engaged by contact 729 connected with the lead of condenser CT through the pincers. If CT passes an appreciable amount of current, coil 133 of relay 135 is energized and contact 135 engages contact 131 and coil 139 of holding relay MB is energized and contact it! engages contact iii to connect solenoid "M5 oi short counter CO3 with A. C. lines I and 2, and contact M4 leaves contact M5 and engages "M6 and a circuit independent of contacts 63%, liil of relay 135 is established from line II] to ground through contacts CIB and 123 of relay C (then closed since relay C is not then energized). If the condenser CT does not pass the flash test. solenoid X is not energized for reasons which will become apparent later and the condenser is ejected.

The following paragraphs describe the cycles of testing the condenser CT.

(A) Cycle for testing a good condenser. Cam m closes switch SW4 (circuit I, Fig. 8) and coil [26 of relay B is connected with line H). Relay B is energized. Contact 125 engages I21 and contact 129 engages 128 and condenser CT is connected with coil 133 of relay 135 (circuit II, Fig. 8). Since CT has no short circuit through it, direct current does not flow and coil 133 is not energized. Contact 135 does not engage T31. Holding relay 14!! is not energized. Condenser CT is charged. Switch SW4 opens and relay 13 opens. Condenser CT is discharged through 729, 124 of relay B and through 122 and C3 then closed of relay C and through coil 750 of discharge test relay REI to ground (circuit V, Fig.

8). RE! is momentarily energized and closes its contacts 151 152 which connect coi-1'T55of test holding relay RE! with line 110 "and ground through the circuit VI (Fig. 8) line Ill, contacts I, 145 (then closed) of relay T49, contacts 75f, 762 of relay 'RE'I, cell "155, and normally closed switch SW3 which is grounded. Contacts 155, I51 of relay 'REZ close to parallel contacts "I51, 152 of relay RE which are closed only for an instant during the discharge test or condenser CT. Relay RE2 holds closed during the capacity test cycle. Switch SW5 (circuit VII, Fig. 8) I is closed to connect coil 123a of relay '0 with line It. Relay C opens its contacts 122, 122a :in circuit V to disconnect condenser CT from c011 150 of relay REI and opens its contacts-1'23, 2 3a in circult III to restore relay 140 to normal, and closes its contactsol'i, 122 (circuit VIII, Fig. 8) to connect condenser CT with the lamp ll-3 and resonant circuit including parts 120 and 12K. Relay RE2 closes its contacts 158, I59 preparatory to the functioning of low capacity test relay RE3 whose coil T60 is connected with the plate 109 of low capacity test tube I. If the capacity of the condenser CT is above the low limit, tube 10! passes current'to coil T50 of relay -RE3 which then closes its contacts 161, I62 and 763, 7134. If the capacity of the condenser is not above the high limit, tube 102 does not pass current to coil 1-" of high capacity test relay RE5 and its contact ill engages 112. Line '2 (circuit IX, Fig. 8) is connected with contacts 158, 753 of RE2 connected with contacts I61, 162 of REB connected with contacts 711,712 of RE5 connected with normally closed contacts IBI, is: of relay A connected with solenoid X connected with line I. Solenoid X is energized and the ejector is disabled and the good condenser CT is not elected.

(B) Test cycle of a condenser which fails to pass the flash test: Condenser CT passes current through coil I33 (circuit II, Fig. 8) and relay 1'35 closes its contacts 136, 131 (circuit III) and passes current through coil 139 of relay 14!) which closes its contacts 144, I46 (circuit III) and closes its contacts MI, 142 (circuit IV) to connect coil 143 of short counter CO3 with lines I and 2. Since the condenser CT has no discharge to ener gize relay REI, solenoid X is not energized and the ejectorremains operative the condenser is ejected.

(C) Test cycle for a condenser which the flash test but not the discharge test. RE] is not energized as in test (A). Relay REE does not close and solenoid X is not energized and the ejector remains operative and the condenser is ejected.

(D) Test cycle for a condenser which passes the flash test, the discharge test, but the capacity is too low. Relay REI and RE? close as in test A, but relay RE3 does not close. Contacts Hit, 152 of relay RE3 being open, lines I and 2 are not connected with solenoid X and the condenser is ejected. Because relay RES was not energized, its contacts 163, 154 remain normally closed, and coil 785 of relay RE l (operating when the capacity is either too low or too high) is energized through the circuit X (Fig. 8) ground, coil I85, normally closed contacts 183, 184 of relay A, normally closed contacts 163, 164 of relay RE3, closed contacts 757, 155 of then energized relay REZ, normally closed contacts I44, 745 of deenergized relay 140, line It. Contacts I85, 187 of relay RE! (circuit XI, Fig. 8) close to connect line In with coil 79!! of relay REt and with ground through .6 normally closed switch SW1. Contacts 19]., 192 of relayR'EB close to parallel contacts 781, 182 of relay R514; and contacts 193 -194 of relay- RES close to connect lines I and 2 with trap valve operating solenoid Y and with counter opera? ingsolenoid I (circuit XII, Fig. 8). Its counter counts a failed condenser and the trap valve operates to cause the ejected condenser to be cliverted from the chute through which descend those condensers which have failed in the short and discharge tests to the chute through which descend those condensers which have failed in the capacity test.

(E) Test cycle for a condenser which passes the flash test low capacity test and the capacity is too high. Coil Tit) of relay IE5 is energized by tube its and contact TH leaves 712 and engages H3 and contact 11 engages H5 (circuit XIII, 8). The energizing circuit of solenoid X is interrupted at FIE-Ill (circuit IX). The trapvalve solenoid Y and the counter solenoid 195 are energized as in test (D) as described with reference to circuits XI and XII.

Relay B is the all-test control relay which first establishes a connection of the condenser with the high voltage D. C. source or between the condenser and a discharge circuit and between the condenser and the resonant circuit.

Relay is the condenser-short-circuit sensing relay which is energized in response to passing direct current by the condenser.

Relay l lil, energized in response to energization of relay 135, is the short counter solenoid (CO3) control relay and also a further test-preventing relay because, if it is energized, relay R2 will not be energized.

Relay R1 is a condenser discharge sensing relay. Relay R2 is a capacity-test-preparaticn relay energized if relay RI is energized and if relay M53 is not energized.

Relay C is a switching-relay for disconnecting the condenser for the discharge circuit and connecting it with the resonant circuit.

Relay RE3 is the suihcient-capacity-sensing relay and relay is the excessive-capacitysensing relay.

Solenoid X is the electromagnet which, if energized, prevents the operation of a device, such as the condenser ejector, which, if it operated would indicate condenser failure because a condenser would be removed from the conveyor.

Solenoid Y is the electromagnet which, if (anergized, would operate a trap valve so that the condenser failing the capacity test would move out the capacity failure chute rather than the short and discharge failure chute thus indicating which of the condenser had passed the shortcircuit and discharge tests but had failed in the capacity test.

A green lamp 796 is connected with lines l and 2 when RES is energized through thefollowing circuit: line i, lamp 195, contacts ltl, 162 or RE3, contacts lee, of REE (holds closed during test). Lamp [96 shows green When the capacity of CT is at the low limit or higher, but does not burn when the capacity of CT is below the low limit. A redsignal lamp is connected with lines 1% and 2 when REll as well as RES is energized through the following circuit: line I, lamp 191, contacts lli, We of energized relay RE5, closed contacts 76!, 352 of energized relay RE3, closed contacts 158, 15s of energized relay R1532. If the capacity of condensers CT is too high both la'fnps 1%, l9! burn.

A relay set switch 198 can be manually closed to contact magnet coil 18!] of relay RE l with line In through the following circuit: ground, coil 18!], normally closed contacts I83, 184 of deenergized relay A, normally closed contacts 163, 164 of deenergized relay RE3, switch I98. line H To adapt the capacity test apparatus for testing condensers having different capacity limits other condensers are connected in the resonant circuit together with the condenser CT. Fig. 4 shows that line i is connected with a padder 8% having condensers 88!, 8412, 803 which can be connected in various ways by switches 8M, (5&5, 866.

. Cam 320 (Fig. 5) has a low land 32% which allows roller 32l and arm to move right by a spring to close normally open switch SW5 which controls energization of relay C for the capacity test which occurs after the flash (shortcircuit) test. Cam Ali! has a low land lllla which allows roller All and lever M2 to move right while roller 32i is on the high land of cam 32% in order to close switch SWd which energizes relay B for the flash test which occurs before the capacity test. After the flash and capacity tests, the bump llllb of cam 5T0 opens switch SW3 to deenergize relay REE if it had been energized. Cam 365 has a low land 450a for receiving roller tfil to deenergize relay RE4 at the time bump imb opens switch SW3 to deenergize relay REE. Roller i 'il and lever 52 move right and switchSWE is closed to energize relay A and the circuit of solenoid X will be broken at NH, 182 momentarily in order to make sure that the solenoid X is deenergized before the test cycles are repeated. Cam 4% has a bump 46th for opening the switch SW i which deenergizes relay RES. Thus at the end of a I revolution of the cam shaft lti the testing cir cuits are restored to normal status.

Summary The machine provides automatic removal at the first ejection station of condensers from the conveyor when they do not pass the tests. The condensers whichare ejected at the first ejecting station pass out a first chute if they have failed to pass the short circuit test or the discharge test; but if they have passed these tests and fail to pass the capacity test because their capacity is either too low or too high, they drop from a second chute. Only good condensers remain on the conveyor.

The machine operated ejector is normally operative, but is disabled automatically by means responsive to the energization of solenoid SOL X which is energized provided four conditions are satisfied, namely (1) Condenser passes short circuit test (relay M0 is not energized) (2) Passes the discharge test (relay R1 32 is energized);

(3) Passes the low capacity test (relay RES is energized);

(4) Passes the high capacity test (relay RES is not energized) Failure to pass the short circuit test causes counter 003 to add.

Operation of the capacity rejection counter CO4 and the trap valve (for descent to the second chute) depends on energization of relay REG which depends on energization of relay RE l which depends on the following:

(a) Non-energization of relay 149 (short circuit test passed) (1)) Energization of relay RE2 (discharge test passed) Either (c) non-energization of relay RE3 (too low capacity) Or ((1) energization of relay RES (too high capacity).

The condenser may pass the short circuit test but, if the discharge test is not passed, RE! is not energized and the condenser drops from the first chute into a container which receives all condensers which have failed in either of these tests.

The test apparatus is automatically controlled by cams operating in timed relation, as follows:

(1) Cam 410 (Fig. 6) operates first, to energize relay B to effect the charging of the condenser by high voltage direct current and then to deenergize relay B to permit the condenser to discharge to coil 15% of relay RE].

(2) Cam 320 operates to connect the condenser into the resonant circuit for the capacity test and to release relay 140 if this relay had been energized because the condenser failed to pass the short-circuit test, and then to release relay C.

(3) Cam 460 operates to open normally closed switch SWI to release relay REG to permit counter solenoid SOL! and trap valve operating solenoid SOL Y to return to normal status.

(4) Cam 410 operates to open normally closed 7 switch SW3 to release relay REZ and cam 460 operates to close normally open switch SW2 which energizes relay A which opens contacts 18!, 182 to deenergize solenoid SOL X (if it had been energized justbefore), and which opens contact 183, led to deenergize relay RE4.

Relays I35 and RE! operate only momentarily.

At the end of the test cycle all relay magnets and all of the solenoids are deenergized and the test apparatus is in condition to repeat the test cycle.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Condenser test apparatus having a resonant circuit for actuation by an alternating current source, said circuit including an inductance and a device sensitive to the amount of current passed by the condenser when connected into the resonant circuit, means for connecting the condenser with the resonant circuit, a first instrument under control by the device and which will pass current when the condenser passes at least a minimum current corresponding to a minimum allowable capacity of the condenser, a second instrument under control by said device and which will pass current when the condenser passes more than a maximum current corresponding to a maximum allowable capacity of the condenser, a first relay energized by current passed by the first instrument, a second relay energized by current passed by the second instrument, a

work holder receiving the condenser while under test, an electromagnet which, if not energized, permits operation of a device indicating capacity test failure, and a circuit established by the energization of the first relay and the non-energization of the second relay for connecting the electromagnet with a current source.

2. Condenser test apparatus having a resonant circuit for actuation by an alternating current source, said circuit including an inductance and a lamp whose light intensity varies according to the amount of current passed by the condenser when connected with the resonant circuit, means for connecting the condenser with the aseasee resonant circuit, two photoelectric cells activated by v the lamp, two thyratron tubes having their grid biases, respectively, under control by the cells and being so adjusted that one tube will pass current when the condenser passes at least a minimum current corresponding to a minimum a owable capacity f t e. ccn e e n that h other ube. will pass. current hen the c nd ns passes more than a maxi-mum current corresp ndin to a. max mum chewab paci y of th nde s r, first. r lay ner y cur passed by the first thyratron, a second relay ene e ed by rrent passe y t nd y o a e ectroma net w ich if not ner zed rm p ration o a dev ce. indic capa tes fai ure, nd a ir uit e t blis by, the en ergization of the first relay and the non-energizat on f e second. relay fo ehhe s the el tromagnet with a current source.

3. Condenser test apparatus having a connec tion to be made with the condenser to be tested, a connection with a high voltage D. C. source, a resonant circuit including the condenser to be tested, an inductance, an A. C. source and a device sensitive to the amount of current passed by the condenser when connected into the resonant circuit, a first instrument under control by the device and which will pass current when the condenser passes at least a minimum current corresponding to a minimum allowable capacity of the condenser, a second instrument under control by said device and which will pass current when the condenser passes more than a maximum current corresponding to a maximum allowable capacity of the condenser, a mechanism for making an electrical connection of the condenser with the test apparatus during the test cycle, a mechanism for making an electrical connection through the test apparatus with a high voltage D. C. source for the short circuit test, a first relay energized in response to the condenser passing appreciable direct current during condenser charge, said second mechanism making electrical connection to effect discharge of the condenser after the short circuit test period, a second relay which is energized provided the first relay is not energized and provided the condenser discharge is satisfactory, a third mechanism for connecting the condenser into the resonant circuit, a third relay energized by current passed by the third instrument, a fourth relay energized by current passed by the fourth instrument, a mechanism which, by its operation, indicates failure of the condenser to pass tests, an electromagnet which,

if energized, prevents operation of the mecha-' nism last mentioned, a circuit connecting the electromagnet with a current source which is established by non-operation of the first and fourth relays and by operation of the second and third relays, and means for operating the mechanisms in timed relation.

4. Condenser test apparatus having a connection to be made with the condenser to be tested, a connection with a high voltage D. C. source, a resonant circuit including the condenser to be tested, an inductance, an A. C. source and a lamp whose light intensity varies according to the amount of current passed by the condenser when connected into the resonant circuit, two photoelectric cells activated by the lamp, two thyratron tubes having their grid biases, respectively, under control by the cells and being so adjusted that one tube will pass current when the condenser passes at least a minimum current corresponding to a minimum allowable capacity of the condenser nd that he the tube will as current when the condenser passes; more than a maximum current correspond g h mum allowable capacity or the condense m cha ism fo akin n l c r cal ehneetie of the on er w th the, t t, appa a us durin the e t c le a me anism f r ma sen electrical connection through the testapparatus with a high voltage 1;). C. source for the short circuit st, a first e ay en r ized, n r e e s to the n a s hs ap re iable di ct c I- rent during condenser charge, said second; A ch,- an m m kin electric l ehh etie te efieet disarge or the c ndenser after he s e circui te p io a second e a W h; i ehet ieee 9 3evided the firs v la s h eliers-iced an accuse h nd n r d schar e s eet siaeterr. a thir me h nism fo ccnhe tine the eeh ser c th r na t r u t, a hird ze hrth passing of current by the thyratron, a fourth relay energized by the passing of current by the second thyr ran, a mechanism which, by its operation, indipates failure of the condenser to pass tests, an electromagnet which, if energized, prevents operation of the mechanism last mentioned, a circuit for connecting the electromagnet with a current source which is established by non-operation of the first and fourth relays and by operation of the second and third relays, and means for operating the mechanisms in timed relation.

5. Apparatus according to claim '3 further characterized by the provision of a second device which, by its operation, determines which of the tested condensers have failed in the capacity test, a second electromagnet which, if energized, causes operation of said second device, a circuit for connecting the second electromagnet with a current source established either by virtue of non-operation of the third relay or by operation of the fourth relay.

6. Condenser test apparatus providing a connection with the condenser to be tested, a connection with a high voltage D. C. source, a resonant circuit including the condenser to be tested, an inductance, an A. C. source and a device sensitive to the amount of current passed by the condenser when connected into the resonant circuit, an all-test control relay for making either a connection between the condenser and the D. C. source or between the condenser and a discharge circuit and between the condenser and the resonant circuit, a condenser short-circuitsensing relay energized in response to passing direct current by the condenser, a further-testpreventing relay energized in response to energization of the short-circuit-sensing relay, a condenser-discharge-sensing relay sensing condenser discharge through the discharge circuit, a capacity-test-preparation relay energized if the discharge-sensing relay is sufiiciently energized and the further-test-preventing relay is not energized, a relay for switching the condenser from the discharge circuit to the resonant circuit, a sufficient-capacity sensing relay energized if current sensed by the device is commensurate at least with minimum allowable capacity, an excessive-capacity sensing relay energized if current sensed by the device exceeds a value commensurate with maximum allowable capacity, a device which by its operation, indicates condenser failure, an electromagnet which, if energized, disables said device, a circuit for connecting the electromagnet with a current source and having a series of connections which are made ing relay if not energized, and. a mechanism which operates to control the timing of the operation said all-test control relay, said capacitytest-preparation relay, said switching-relay and said device.

7. Apparatus according to claim 6 having also a tell-tale relay which is energized in response either to non-energization of the sufficientcapacity-sensing relay or to energization of the 'excessive-capacity-sensing relay, a second device which, by its operation, indicates which ones of the condenser failures are capacity-test failures, T

a second electromagnet which, if energized cause operation of said second device, and means for connecting the second electro-magnet with a current source and rendered operative if the tell-tale relay is energized.

FLOYD J. FOUST. WILLARD C. SHAW. HILTON J. MCKEE. WARREN M. RIDER. J. S. BURGE.

12 REFERENCES CITED The following references are of record in the file of this patent:

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